1,122 research outputs found

    Conservation and Ecotourism in Brazil and Mexico: The Development Impact

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    Conservation projects alter local productive modes and have an impact on livelihoods. For example, sea turtle conservation projects affect fishing communities through hunting restrictions. It is not painless for communities to improve fishing technology in order to prevent the accidental capture of sea turtles. The inability to adapt to environmental requirements forces fishermen to abandon traditional livelihoods. A combination of environmental conservation and ecotourism development can provide the solution. (...)Conservation and Ecotourism in Brazil and Mexico: The Development Impact

    Waking Dream: Cornell, Langstaff Gateway and Planning New Suburbs in the GTA

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    This paper explores the gaps between anti-sprawl policies and what has materialized on the ground in the Greater Toronto Area, a matter of particular import as the province's suite of growth management legislation is now being tested in its implementation phase. As Toronto grew so did Markham as one of the sprawling bedroom communities along its border. But in the 1990s the town became among the first municipalities in Canada to adopt New Urbanism as a paradigm for suburban development, attempting to break away from decades of auto-centric urban sprawl. Andres Duany and his firm, Duany Plater-Zyberk (DPZ), were hired to develop Cornell, a greenfield site, as a Traditional Neighbourhood Design (TND) New Urbanist community, with a greater emphasis on compact development and walkability than conventional development. In 2005-06, the Province of Ontario passed new legislation that enshrined the same Smart Growth principles in the planning regime for Toronto and its surrounding region. Even as questions were being raised about how successful were the ideals of New Urbanism generally, and the development of Cornell specifically, Markham hired Peter Calthorpe, also a founder of New Urbanism, but with a greater focus on orienting communities around transit corridors than Duany. Operating in the new provincial growth context, he planned Langstaff Gateway, a proposed Transit-Oriented Development (TOD); a suburban community in which only 35 per cent of trips would be by car. This paper reviews literature on the paradigmatic "American Dream," that drove the dominant form of conventional suburban development and the New Urbanist ideals that aim to supplant it. It then proceeds to assessments of the nascent Cornell community and the planned Langstaff Gateway growth centre through interviews conducted with residents, politicians, members of the development industry and planners. Few if any of the suburban municipalities around Toronto have been as amenable as Markham to introducing new suburbs and the new kind of lifestyle that comes with them. After deploying ideas for "better" suburban development for nearly two decades the city provides a unique case study through which to assess what has gone right and what has gone wrong on the ground. This paper then looks observes trends in changing suburbia, both in terms of the lifestyle of its residents and the built form in which they reside. Intensification and transit-orientation are the new goals of the provincial planning regime but this paper will look at how realistic those goals are and, learning from Markham's example, what tools or other changes are required to close the gap between expert plans for more sustainable and successful suburbs and the realities of politics and the market. After nearly 20 years of trying, how successful have attempts to implement New Urbanist ideals for "better" suburban development been and what are the gaps between their ideals and the reality as it has materialized? How has the policy regime in Ontario addressed these shortfalls and what changes are required to ensure those gaps are filled

    Classification of Material Mixtures in Volume Data for Visualization and Modeling

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    Material classification is a key stop in creating computer graphics models and images from volume data, We present a new algorithm for identifying the distribution of different material types in volumetric datasets such as those produced with Magnetic Resonance Imaging (NMI) or Computed Tomography (CT). The algorithm assumes that voxels can contain more than one material, e.g. both muscle and fat; we wish to compute the relative proportion of each material in the voxels. Other classification methods have utilized Gaussian probability density functions to model the distribution of values within a dataset. These Gaussian basis functions work well for voxels with unmixed materials, but do not work well where the materials are mixed together. We extend this approach by deriving non-Gaussian "mixture" basis functions. We treat a voxel as a volume, not as a single point. We use the distribution of values within each voxel-sized volume to identify materials within the voxel using a probabilistic approach. The technique reduces the classification artifacts that occur along boundaries between materials. The technique is useful for making higher quality geometric models and renderings from volume data, and has the potential to make more accurate volume measurements. It also classifies noisy, low-resolution data well

    Partial-volume Bayesian classification of material mixtures in MR volume data using voxel histograms

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    The authors present a new algorithm for identifying the distribution of different material types in volumetric datasets such as those produced with magnetic resonance imaging (MRI) or computed tomography (CT). Because the authors allow for mixtures of materials and treat voxels as regions, their technique reduces errors that other classification techniques can create along boundaries between materials and is particularly useful for creating accurate geometric models and renderings from volume data. It also has the potential to make volume measurements more accurately and classifies noisy, low-resolution data well. There are two unusual aspects to the authors' approach. First, they assume that, due to partial-volume effects, or blurring, voxels can contain more than one material, e.g., both muscle and fat; the authors compute the relative proportion of each material in the voxels. Second, they incorporate information from neighboring voxels into the classification process by reconstructing a continuous function, ρ(x), from the samples and then looking at the distribution of values that ρ(x) takes on within the region of a voxel. This distribution of values is represented by a histogram taken over the region of the voxel; the mixture of materials that those values measure is identified within the voxel using a probabilistic Bayesian approach that matches the histogram by finding the mixture of materials within each voxel most likely to have created the histogram. The size of regions that the authors classify is chosen to match the sparing of the samples because the spacing is intrinsically related to the minimum feature size that the reconstructed continuous function can represent

    Conservation et Écotourisme au Brésil et au Mexique : l?impact du Développement

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    Conservation et Écotourisme au Brésil et au Mexique : l?impact du Développement

    Conservação e Ecoturismo no Brasil e México: O Impacto Sobre o Desenvolvimento

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    Conservação e Ecoturismo no Brasil e México: O Impacto Sobre o Desenvolvimento

    Conservación y Ecoturismo en Brasil y México: Impacto Sobre el Desarrollo

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    Conservación y Ecoturismo en Brasil y México: Impacto Sobre el Desarrollo

    The impact of electoral administration on Brazil’s political system

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    En este artículo se describen los procedimientos y el desempeño del órgano de administración electoral de Brasil –TSE– después de su instalación definitiva en 1946, y la gestión de las elecciones antes de esa fecha. Este análisis pone de relieve el papel del TSE en la conciliación política durante períodos críticos, antes y después del golpe militar de 1964, durante la transición del régimen militar (1974-1985) y durante el período posterior a 1985. Los «perdedores» en las elecciones durante estas tres etapas nunca cuestionaron la legitimidad del sistema de gestión electoral. En varias ocasiones, el TSE implementó la modernización del proceso electoral para reducir la tutela sobre los votantes y mejorar la confianza en el sistema. Por último, desde 2002, el TSE viene practicando la «judicialización» de la política. _____________________________________________________________________________________ ABSTRACTThis article describes the operations and performance of Brazil’s election management organ –the TSE– after its definitive installation in 1946, and its management of elections before that date. This analysis highlights the TSE’s role in political conciliation during critical periods, before and after the military coup in 1964, during the transition from the military regime (1974-1985), and during the post-1985 period. The «losers» in elections in these three periods never contested the legitimacy of election system management. On several occasions, the TSE implemented modernization of the election process to reduce tutelage over voters and improve confidence in the system. Finally, since 2002, the TSE has practiced «judicialization» of politics
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